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Debugging can indeed be discouraging, but please don't give up.? We'll continue to help. If you limit your current to 250-300mA, it can't burn up the BS170s - it also won't give full power out, but

Lifting one end is a good way to lift the opposite pad. I would suggest making a tool consisting of a "U" shape of heavy-ish solid wire whose legs would closely straddle the diode contacts, tinned at

Jamie, hope all is well following your surgery!? In summary, I removed C17 and inserted a wire into the now empty PCB hole connected to R6.? That wire runs to the ring terminal of an 1/8" TRS jack

Jerry, Thanks.? I'll give it a try as soon as I can (probably over the weekend). 73, Mike, KL7MJ

I put you on the list... Note that if we do a group buy again, we will either do V2 or V1.2, but not both. Still evaluating V2 design performance... Stan KC7XE

No.? L102 and C106 filter the voltage, trying to average it, so it won't go down to zero. But this is BAD, and needs investigation before replacing D109. The processor produces PWM (the PWM_3V3

Hi Joel. I'm wiring up my Pacific Antenna mic now.? The manual says that the bare wire is ground, but there is no bare wire :-) Mr. Ohm Meter says: RED = TIP and I understand that TIP is PTT. WHITE

For a few seconds maybe. It is a small chip capacitor in a tiny metal case. Not designed to dissipate any power. Real Dummy Loads are easy to make. Twenty 1k quarter watt resistors in parallel make

I have successfully removed D109 on QMX+ using this technique.? I first used some 60/40 solder on both ends of the diode, with a hot iron, to melt the lead-free surface-mount solder, and mix it with

I noticed the same issue, but raising the VOX Threshold to about 35 or higher completely resolved the issue, and it was still plenty sensitive for my voice (though this probably depends on the

Maybe you could buy a pack of 10 units from QRP-Labs shop, you would be sure to get the good devices. 73 - Pierre - FK8IH

It's actually L515 and L516 (20/17/15) that have a number of turns lower than their 'design' inductance. L517 and L518 are right on target. You can see this by using toroid.info to calculate the

I had to replace a failed IC403, so that is a possibility.? In my case it was caused by a probe-slip while I was measuring something, which caused an over-voltage on Vcc.??? Kai, if you think

Glad to find some traffic on this topic. I am surprised these coils have similar number of turns to the 20/17/15 meter LPF. and likely wrong inductance. but a few thousand rigs before me, I will

The SMA terminator which comes with the NanoVNA can only withstand 1W, maybe 2W Max. ________________________________ Sent: Monday, April 21, 2025 10:58:54 PM To: [email protected]

"I'm using an SMA terminator which came with my NanoVNA." Are you shure that this dummy-load can withstand the output-power of the QMX (up to 5W!)? 73, Wolfgang

Joerg, Yes, both your 3.3V and 5V SMPS are failed.? You may want to order another set from qrp-labs (they are inexpensive) if you don't want to replace components. And what Jason said is important,

Joerg, wich rev. is your QMX? First batches were made with 6.3V rated C107 and later batches with 10V rated. I have a rev. 2 HB QMX and C107 burned similar to yours. As a precaution I switched both

Your C107 is a 6.3 V spec. (I can see by the one on the 3.3 V board - not an issue there.) I had one blow early on and it took out a few other things on the 5 V SMPS. I repaired it, but testing showed

Very strange. Please check it you really tested pin 4. Pin 5 is on the same side of the case and is connected to 3.3V. The signal from pin 1 is going to pin 4, for IC502 with the same timing and for